M&S Bank credit card customers are threatening to boycott the store over its heavy-handed demands to prove their identity.

Money Mail revealed earlier this month how customers are being asked to submit documents signed by an independent professional decades after opening accounts. Some have had a card with the bank since the Eighties.

M&S Bank says it is part of a crackdown on identity fraud, as many longstanding customers applied for credit cards before it introduced tougher ID checks. However, customers say the HSBC-owned bank has ‘lost the plot’ and plan to cut up their cards.

M&S Bank says the identity checks are part of a crackdown on identity fraud, as many longstanding customers applied for credit cards before it introduced tougher ID checks

Some have been asked to travel up to 100 miles to hand over documents at a branch.

The bank is asking for two forms of ID, including household bills, passports and driving licences. It is also demanding customers find a professional worker who knows them to verify that the documents are genuine.

This person also has to provide personal information, including a signature, name and date, their occupation, employer’s name, company address, phone number and the certifier’s professional registration number, for example, a doctor would have a General Medical Council reference code.

Many retired customers say it is a huge hassle to photocopy documents and find someone to verify them. But if they do not comply, M&S Bank says they may be unable to use their cards.

Jackie Keay, 72, of Yateley, Hampshire, felt unhappy about finding someone to countersign her papers.

She says: ‘I sing in a choir at the military academy Sandhurst, so I could have asked someone there.

‘But I was very uncomfortable to ask them all that information about their address and company address and registration numbers. It seemed silly.’

In the end, she called the bank, which said she could visit an M&S branch instead.

‘They should have had that option on the letter in the first place,’ says Jackie.

IT worker Keith Abbott, 61, of Poole, Dorset, has stopped using his card in protest.

Keith, who has had an M&S card for more than a decade, says: ‘I have never heard of a bank doing this to loyal customers who have held accounts for many years.

‘They have also dramatically reduced the points they award on their cards, so we have had enough. After we received the letter, we opened a joint credit card with Barclaycard, which offers better rewards.’

Under changes introduced in February, M&S Bank credit card holders now get just one point for each £5 spent outside of M&S stores. Previously, they only needed to spend £2.

Hassle: Warren Miskin, left, and Jackie Keay are unhappy with M&S Bank’s ID checks

This means cardholders have to spend £500 elsewhere to earn just £1 in rewards.

The letter sent to customers about ID checks asks for copies of personal documents to be sent to M&S by post in a prepaid envelope. Many felt this was insecure.

When they complained, the bank told them to take the papers into their nearest branch — although it has just 29 across the UK.

This means customers may have to travel very long distances.

Retired insurance broker John Powell, 80, of Oswestry, Shropshire, has used his M&S credit card to buy food in-store every week for 15 years. He was surprised to get a letter in October asking him to prove his wife Maureen’s identity as a second cardholder.

He photocopied her driving licence and a council tax bill. But, as most of their friends are retired, they did not know a professional worker to verify the documents.

The pair called M&S Bank, which said they could get their papers signed by an M&S shop manager. But it was not encouraged.

When John was turned away by his local Simply Food store, he was told by M&S Bank to make the 66-mile round trip to his closest branch at Cheshire Oaks.

He says: ‘I can’t understand why they want to check up on my wife of 52 years. I told M&S Bank that my wife is the only Mrs Powell I have ever had, but they didn’t seem to appreciate that.’

After he sent several letters, M&S Bank finally replied, saying: ‘If you do not provide the requested information, your account will not be affected.’

John says: ‘So why ask in the first place? I know they want to prevent fraud, but this is like using a sledgehammer to crack a nut.’

Warren Miskin, 65, from East London, received a letter six weeks ago from M&S asking for wife Tina’s ID. He initially thought it was a scam, as the letter came from the bank’s Chester office, but wanted the identification documents to be sent to a Bristol address.

Warren wrote to M&S Bank, which confirmed it was genuine and said it needed ‘physical evidence’ of his wife’s identity to protect against financial crime.

He says: ‘I can’t be bothered with the hassle — we will use our other credit cards instead. Why do they need this information so suddenly? Has something happened?’

M&S Bank insists the letters were not prompted by a security breach and is simply updating its records as an anti-fraud measure.

It said those who refused to comply would have the same level of fraud cover for now, but may not be able to use the cards in future.

A spokeswoman says: ‘If a customer is unable to provide the information requested, we could potentially, in some circumstances, restrict the services we’re able to offer them, but this would always be a last resort.’